The present invention generally relates to an apparatus and a method for processing food products and to generally improve the time constraints required for processing such food products by providing a rapid cycle, low cost, controlled method which represents a substantial improvement over previous devices and methods. More specifically, the invention relates to an apparatus and a method for producing a frozen crust surface on a loaf or stick-shaped meat product using a refrigerated heat exchange surface for direct, pressure-controlled contact with the surface of the food product. The invention provides a rapid cycle, low cost, controlled method and an apparatus for producing a frozen crust condition on the food loaf prior to slicing. Subsequent slicing of the crusted food product provides a significant improvement in slice quality and allows a faster slicer output for many applications.
In the preparation of sliced meat products, for example, the end product is often prepared by slicing a previously formed loaf or log. In the preparation of such sliced products, it has been recognized that certain advantages can be realized during the slicing step if the loaf is at least partially frozen when sliced. In particular, it would be desirable to form a frozen crust along at least a portion of the outermost surface of the loaf. It would also be advantageous to form such a frozen crust using freezing technology which could be efficiently utilized within a manufacturing line to form a frozen crust within seconds rather than minutes, quickly preparing the loaf for subsequent slicing. While cooling or freezing processes are known, existing technologies have failed to provide suitable systems or devices to rapidly produce frozen crust conditions on loaf products prior to slicing.
Available devices and processes for cooling or freezing certain food products have generally attempted to provide relatively quick cooling or freezing times for certain foods while also preserving food quality such as taste, texture and the like. Cryogenic freezing and cooling has employed the use of heat exchangers, utilizing a circulating coolant such as carbon dioxide, liquid nitrogen, ammonia or the like to maintain a maximum temperature differential between the unfrozen food product and the heat exchange surface. Yet, the utility of heat transfer technology in the preparation of sliced products has been limited by excessively lengthy freeze time requirements and the need for bulky and expensive equipment. For example, the time requirements for adequately preparing certain crusted meat products using existing heat exchange devices has typically exceeded five or more minutes. Available heat exchange devices have been quite bulky, requiring sealed cabinets, tunnels and other enclosed cabinet-like structures which require much space, are complicated in their operation and are quite costly.
The present invention overcomes the noted problems of the prior art by providing an apparatus and process for cryogenically crusting certain loaf products prior to slicing. The apparatus is adapted for inclusion in a process line and specifically for producing a frozen crust surface on a loaf or a log product by compressing the loaf against a refrigerated heat exchange surface. The crusted loaf may then be sent downstream to a slicer where the frozen crust improves slicing conditions, producing a sliced product of higher quality than was previously available and, in some applications, allowing for a faster slicer output. The apparatus and method of the invention provide a rapid cycle, low cost, controlled means for producing a frozen crust and the apparatus requires less operating space in comparison to bulky prior art commercial cabinet systems, making it well-suited for inclusion in an automated continuous loaf product slicing operation.
In a preferred embodiment, a heat exchanger is provided with a shaped contact surface and the heat exchanger is positioned to support a food loaf directly on the contact surface. Refrigerant is circulated continuously through the heat exchanger, maintaining the contact surface at a fairly constant low temperature. A retractable clamp applies pressure to the opposite side of the food loaf to compress the loaf against the refrigerated contact surface and thereby accelerate the crusting cycle. After a short cycle time of between about 30 and about 90 seconds, the clamp can be retracted and the loaf can be ejected onto a slicer, located downstream, by a sliding or dumping action. The cycle can then be repeated for the next loaf and the contact surface can be periodically scraped to remove any frost build-up.
In an alternate embodiment of the invention, a movable second refrigerated heat exchanger is used in place of the retractable clamp to compress the food loaf against the contact surface of the first heat exchanger while simultaneously crusting one or more of the additional sides of the loaf.
Accordingly, it is an object of the present invention to provide a process and an apparatus for the preparation of certain food products.
It is another object of the present invention to provide a process and an apparatus utilizing a refrigerated heat exchange surface for producing a cryogenically frozen crust condition to at least a portion of the outer surface of a food loaf.
It is another object of the present invention to provide an apparatus and process for the preparation of food products which can be included in a process line.
It is another object to improve the quality of food products sliced from a loaf by providing an apparatus and process for rapidly imparting a frozen crust condition to the food loaf prior to slicing.
These and other objects of the present invention will be more fully understood and appreciated upon a consideration of the remainder of the disclosure, including the drawings and the detailed description of the preferred embodiments.